Software for the
people who run it.

Generating a CLI from an API spec is a solved problem. Tools like Printing Press will build you one from a URL in about ten minutes, and for a documented API that is genuinely the right answer. I would use it. Nobody should be paid for typing out endpoints a machine can read.

The interesting work starts where the spec runs out. A commerce platform I sell through publishes a small public API covering products and sales. Everything that actually matters to an operator sits behind the dashboard and appears in no specification anywhere: payout scheduling, refund and chargeback handling, license lifecycle, seller fraud signals, enforcement actions.

So I built the client that should have existed. 179 commands, 57 of them against admin surface with no public documentation, reverse-engineered from the network layer, with a man page for every one.

• The hard part was never the code. It was working out what each undocumented call did, which ones were destructive, and which combinations were safe to run unattended.
• Undocumented means unversioned. Nothing warns you when it changes, so the client has to fail loudly and specifically rather than silently do the wrong thing to somebody's payout.
• Some of it should not be automated at all. Refunds and enforcement stayed manual on purpose. Knowing where to stop is the judgment a generator cannot supply.

Publishing a product went from a fifteen minute clickthrough to one command. Sales and payout reporting became scriptable instead of a screenshot. But the transferable point is not the CLI: it is that "the vendor's tool does not do that" is a starting position, not a conclusion.